It is the objective of this study to determine the effect of chronic sympathetic nerve stimulation on kidney function of conscious dogs. The experimental model will be prepared by the surgical anastomosis of the left phrenic nerve to the left splanchnic nerve, and the urinary bladder divided into two hemi-bladders each draining one kidney through cystostomy tubes in the abdominal wall. Following reinnervation of the left renal plexus, the nerve supply of the left kidney may be stimulated to varying degrees during normal breathing and heat-induced panting or eliminated by a left phrenic nerve block in the neck. The nerve supply to the right kidney is unaffected by this procedure, so it may serve as the control organ during the subsequent studies. The effect of sympathetic stimulation on glomerular filtration rate, renal hemodynamics, tubular transport mechanisms, renin secretion, and systemic blood pressure will be observed. These functional characteristics of the chronically stimulated kidney will be re-examined following surgical removal of the contralateral normal kidney. These studies are expected to provide an insight into the effect of the sympathetic nervous system on renal function in those clinical conditions associated with high sympathetic nervous system activity such as congestive heart failure and various forms of shock. Studies of blood pressure changes in the animal with a single chronically stimulated kidney may add to our understanding of hypertension in humans.